My recollection is that they weren't shipping from Thailand via USPS, but were doing packet shipping (i.e. ship a big box of pre-packaged orders to a company in Colorado that would open the box and hand the individual packages over to USPS). I haven't noticed a meaningful change in USPS prices over the last few years, but the cost for low-skilled warehouse labor has definitely gone through the roof. A couple of other Asian vendors that used to do packet shipping have stopped over the last year, so I suspect that packet shipping prices are the likely culprit.